This invention relates to a hydraulic coupling device for connection to a multi-line hose constituted by a plurality of hydraulic conduits bunched together. The invention is particularly useful in the hydraulic distribution systems used in underground mine workings, particularly for hydraulically advanceable mine roof support assemblies and other hydraulic appliances.
Systems are known in which numerous hydraulic conduits are bunched together to form multi-line hoses. Multi-line hoses are interconnected by means of pairs of complementary hydraulic coupling devices. One coupling device of each pair houses a plurality of male plug pins which are attached to the conduits of one multi-line hose; and the other coupling device of that pair houses a plurality of female plug pins which are attached to the conduits of a second multi-line hose. The female plug pins mate with the male plug pins when the two coupling devices are attached (usually by the interengagement of complementary screw threads on their casings), thereby connecting the two multi-line hoses.
In one known hydraulic coupling device, the plug pins are held within the casing of the device by means of a pair of retaining discs, the plug pins passing through off-set holes in the retaining discs. The plug pins are either securely held, or held with slight play, between flanges provided on the retaining discs. Unfortunately, such retaining discs need to be differently shaped to enable them to hold the plug pins. This leads to increased production and storage costs. Moreover, the retaining discs have complicated shapes, so that the production costs are increased further. Furthermore, assembly of this type of hydraulic coupling device is difficult.
The aim of the invention is to provide a hydraulic coupling device which does not suffer from these disadvantages.